I’m getting ready to get serious about finding a 518 for my 37 dodge PU project. The truck will be powered by a naturally aspirated 331 Hemi, 10:1 compression and a SWAG is 350 HP/400TQ. The rearend is a Dana 60 with 4.56s (overkill I know but I had it). It will live mostly on the street, but occasionally taken to the strip, probably with a set of slicks.


Ideally what I hope to find is a complete donor truck that I can drive before I buy to make sure the transmission works OK before I pull it out (it will make it easier knowing the transmission is good when I go to wire up the OD and possibly lockup.

My first question is what year should I look for? One source says 88-93 and another says up to 95.

My initial thought is to find one with a lockup convertor. My thinking is the lockup should help keep transmission temperatures down on the highway. I also suspect the convertor will be a little looser than a non-lockup unit. I’ve heard the early lock up units were problematic. Are there years to stay away from, and will a lock-up convertor live if only used for highway driving?

What upgrades are recommended for the 518 itself …..I’m looking more for recommended durability mods rather than turning it into an all out race transmission. What is a good shift kit for these?

Should I just say the he!! with it and throw a 4 speed in it

Thanks

The LU will be fine if you use type f fluid so it does not slip and burn, it will also help the other clutches live longer.

A good tranny cooler to cool the oil more after it comes out of the radiator will help.

I always open the lube hole in the out put shaft to cool/lube the OD section better.

If you are going into the trans and willing to spend some money you should install flat snap rings instead of the wavy ones. Billet acumulator and band apply servos are good, they make every thing apply nice and firm, if you really want the heaviest duty stuff, buy a case that will fit the hemi and buy a diesel tranny and swap all the diesel guts into the case.

I wouldn't use type F in an overdrive, it lacks the lubrication properties needed for the constantly running overdrive planetaries.

'95 was the last year of the 518 and that's the best one to get.

The lockup affects your torq coverter choice. None of the stock converters were terribly loose or performance oriented. If you want a bit higher stall, the non lockup 518 will take a regular 727 converter but the LU version takes it's own converter and higher stall ones are more money.

I would rebuild the transmission while I had it out already, but if you don't want to, I'd at least install the transgo shift kit for the 518.

There's a guy on Ebay that sells az 2400-2800 stall converter for the lu 518. I paid $175 for one and it really worked well behind my 408 stroker.

Thanks for the information guys. Like I said my thoughts are to try to find a known good transmission and install it while the truck is in mockup. That way I can get the wiring sorted out for the LU/OD and get an idea about what the engine will like for stall.

As light as the truck will ink the truck be and especially with the 4.56s I really don’t the truck will need or want a lot of stall, but you never know until you can drive them.

Once I get everything dialed in I’ll be taking the truck apart for paint and body and at that time looking at going thru the transmission for at least a shift kit or possibly a rebuild. Are there any other shift kit recommendations for a shift kit other than a Transgo?

The gutting a diesel trans and putting the internals into a 318/360 case sounds interesting. I have a good bare case sitting in the truck now. I assume the years I would be looking for would be the same as for the ones going behind a gas engine? Is this a straight transfer of internals or are there other mods that need to be made?

Just a reminder, 518s need 3/8" cooler and lines.

Rick

it may be easier to find a V10 trans at a reasonable price than the diesel and it has the same stuff with the right governer weight---i think they are correctly called a 618---after you peel either down the bare case and torque converter are worth money---bob

Wiring is super simple. 12v to one side of a normally open vacuum swith from an on off toggle. Wire from V switch to center terminal of the 3 wire conector on the side of the trans. One wire to each of two pressure switchs plumbed into the govener port on the pasenger side of the trans. GO to the PATC trans site for a easy to follow diagram.